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为了研究大直径抽采钻孔套管护孔技术,以同煤集团塔山矿三盘区首采面为研究背景,采用理论分析、数值模拟和现场验证相结合的方法进行研究,根据塑性理论,推导了钻孔套管塑性区应力场的解析解和“套管-围岩系统”的极限强度表达式;运用FLAC~(3D)软件分析了有、无套管护孔2种情况时,大直径钻孔的应力分布规律,并且通过现场进行了验证;结果表明,随着采面的推进,不管有、无套管护孔,采动对大直径钻孔的影响强度及范围逐渐增大,并且有套管护孔时极限强度比无套管护孔时最大能达到3.47倍。
In order to study the large-diameter borehole casing protection technology, taking the first mining face of Sanpan District of Tashan Mine of Datong Coal Mining Group as the research background, the method of theoretical analysis, numerical simulation and field verification was used to study. Based on the plastic theory, The analytical solution of the stress field in the plastic zone of the bored casing and the ultimate strength expression of the “casing-surrounding rock system” are deduced. By using FLAC 3D software, , Large-diameter borehole stress distribution, and verified by the site; the results show that, with the advance of mining face, regardless of there, no casing protection hole, mining on the large diameter borehole impact strength and gradually increased Large, and the casing when the ultimate strength than the casing without casing when the maximum can reach 3.47 times.